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Min Gap Between Two Pipes on a Pipe Rack

02/07/2013 11:00 PM

What is the minimum gap to be maintained between two adjacent pipe lines going on a pipe rack??? Can anyone give me a reference standard for that?

Also, what is the minimum gap between two insulated lines?

What is the minimum gap between an insulated and a non insulated line?

Please give your comments with any reference standards.

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Guru
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#1

Re: Min gap between two pipes on a pie rack

02/07/2013 11:14 PM

Zero.

More practically, you might want to leave enough room to get a paintbrush or roller between adjacent pipes. Some contract specifications may may call this out, but I don't know of any widely accepted standards that might exist.

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#2

Re: Min gap between two pipes on a pie rack

02/08/2013 3:01 AM

I would consider the space required for the fixation system, in example U-bolts, and the dimensions of elements to be assembled with the pipe, sometimes bigger than the pipe itself.

In example valves, strainers, flowmeters... etc.

Do this elements require maintenance??

Cases may differ greatly depending on the pipe and the fluid.

Hydraulic pipes are comparatively small, but hydraulic elements are huge in comparison.

Salu2 cordiales,

Abel

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#3

Re: Min gap between two pipes on a pie rack

02/08/2013 4:28 AM

Min gap between two pipes on a pie rack

Small enough to stop the pies falling through.

Sorry couldn't resist.

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#4
In reply to #3

Re: Min gap between two pipes on a pie rack

02/08/2013 5:52 AM

Unless he is installing a piecost... Than the distance must be increased.

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Guru

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#5

Re: Min Gap Between Two Pipes on a Pipe Rack

02/08/2013 8:06 AM

An addition to abelmh's list is differential expansion, one pipe expanding and the adjacent one not expanding, this can be a big proble with bends at the end of long straights.

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#6

Re: Min Gap Between Two Pipes on a Pipe Rack

02/08/2013 1:28 PM

The common "ROL" (Rule of Thumb) is:

a). Uninsulated lines of equal or near equal size and Flange Ratings: "Flange to pipe + an inch" This is Largest Flange (radius) to smaller Pipe (radius) plus an inch (25mm).

b). Hot Insulated lines of equal or near equal size and Flange Rating with the smaller line being Hot Insulated: "Flange to Pipe + Insulation + an Inch" This is the largest flange (radius) to smaller Pipe (radius) + Insulation (thickness) of the smaller line + an inch (25mm).

c). Cold Insulated lines: "Flange to pipe + Flange Insulation + Pipe Insulation + an Inch" Largest line Flange (radius) plus Cold Insulation thickness on the flange plus the other line size (radius) plus thickness of Cold Insulation on the pipe plus one inch clearance.

d). That all worked fine for many , many years. But now there are a lot more high pressure systems in plants that can and do upset the old ROT thinking. Now for all cases the Piping Designer needs to check for the presents of the very high pressure lines and the possibility of flanges in the Pipe Racks. When this case exists the "Worst Case" rule comes in to play and it affects uninsulated and insulated lines equally. Here the rule is: "Worst Case Flange extension to pipe plus an inch (plus insulation if applicable)" The definition of the Flange extension is the difference between the radius of the pipe to the radius of the Flange. Check both lines for the Worst case.

Go here, (Bottom of the list) for a chart for "Quick Worst Case Flange Extension" http://pipingdesigners.com/Tools%20-%20section%209.htm

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#7
In reply to #6

Re: Min Gap Between Two Pipes on a Pipe Rack

02/08/2013 11:27 PM

What do the codes/standards(US,UK,Gerrnan etc)say?.

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#8
In reply to #7

Re: Min Gap Between Two Pipes on a Pipe Rack

02/09/2013 7:13 AM

Pipe Spacing in pipe racks or in other locations in a plant is not an issue that is addressed in the ASME B31.? Piping Codes. It is also not an issue addressed in any of the API Standards.

The only place you will find this issue covered would be in Client or Engineering Company design Standards.

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#9

Re: Min Gap Between Two Pipes on a Pipe Rack

02/09/2013 8:08 AM

how long is a piece of string ??

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#10

Re: Min Gap Between Two Pipes on a Pipe Rack

02/11/2013 9:59 AM

The first question is what are the standards and codes for the location where the pipe rack will be installed.

Next the standards and codes of the design engineering or client.

Finally Rule Of Thumb indicating enough space to be able to tighten flanges, tighten bolts holding the pipes to the rack, enough space to fit hands, tools, and paint brushes in between the pipes.

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#11

Re: Min Gap Between Two Pipes on a Pipe Rack

02/18/2013 9:22 AM

If it's welded pipe don't forget about the welder making the field welds. The larger the bore the more room he/she would need. When I detail raceways for pipe most the spacing is driven by welder access.

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Users who posted comments:

abelmh (1); Anonymous Poster (1); JPool (1); passingtongreen (1); PennPiper (2); pipeit (1); pnaban (1); Randall (1); Tornado (1); vargaalex (1)

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